Key Methodological Research

Causal Inference and Propensity Score Methods

By utilizing the Pearson distribution system [1,2], I derived a more accurate approximation than traditional approximations to the distribution of the product of two dependent correlation coefficients [3]. Subsequently, I used this innovative approximation method to develop a probability index of the robustness of causal inference [4]. This research addressed an important topic and developed the promising idea of using information about observed confounders to measure the robustness of a causal inference from observational studies to unobserved confounders. Later, I extended my methodological contributions to causal inference by tackling both methodological and practical issues in propensity score methods, a statistical technique for reducing selection bias so as to increase the validity of causal inference from observational studies [5,6,7,8]. Finally, by integrating the Pearson distribution approach to investigating unobserved confounders [4] into propensity score estimation models, I addressed concerns about the sensitivity and robustness of propensity score estimation to uncontrolled confounders [9].

  1. Pan, W. (2009). A SAS/IML macro for computing percentage points of Pearson distributions. Journal of Statistical Software, 31(Code Snippet 2), 1-6.
  2. Yang, Q., An, X., & Pan, W. (2019). Computing and graphing probability values of Pearson distributions: A SAS/IML macro. Source Code for Biology and Medicine, 14, 1-6.
  3. Pan, W., & Frank, K. A. (2004). An approximation to the distribution of the product of two dependent correlation coefficients. Journal of Statistical Computation and Simulation, 74, 419-443.
  4. Pan, W., & Frank, K. A. (2003). A probability index of the robustness of a causal inference. Journal of Educational and Behavioral Statistics, 28, 315-337.
  5. Pan, W., & Bai, H. (Eds.). (2015). Propensity score analysis: Fundamentals and developments. New York, NY: Guilford Press.
  6. Pan, W., & Bai, H. (2015) Propensity score interval matching: Using bootstrap confidence intervals for accommodating estimation errors of propensity scores. BMC Medical Research Methodology, 15(53), 1-9.
  7. Pan, W., & Bai, H. (2016). Propensity score methods in nursing research: Take advantage of them but proceed with caution. Nursing Research, 65(6), 421-424.
  8. Pan, W., & Bai, H. (2018). Propensity score methods for causal inference: An overview. Behaviormetrika, 45(2), 317-334.
  9. Pan, W., & Bai, H. (2016). A robustness index of propensity score estimation to uncontrolled confounders. In H. He, P. Wu, & D. Chen, (Eds.), Statistical causal inferences and their applications in public health research (pp. 91-100). New York, NY: Springer.

Power Analysis and Resampling

Through mentoring my advisees, we have tackled important issues in statistical inference in general [1] and also in some specifics, such as power analysis [2], effect size [3], and resampling [4,5,6,7].

  1. Sun, S., & Pan, W. (2011). The philosophical foundations of prescriptive statements and statistical inference. Educational Psychology Review, 23, 207–220.
  2. Sun, S., Pan, W., & Wang, L. (2011). Rethinking observed power: Concept, practice, and implications, Methodology: European Journal of Research Methods for the Behavioural and Social Sciences, 7(3), 81-87.
  3. Sun, S., Pan, W., & Wang, L. (2010). A comprehensive review of effect size reporting and interpreting practices in academic journals in education and psychology, Journal of Educational Psychology, 102, 989-1004.
  4. Bai, H., & Pan, W. (2008). Resampling methods revisited: Advancing the understanding and applications in educational research. International Journal of Research & Method in Education, 31(1), 45-62.
  5. Bai, H., & Pan, W. (2009). An application of a new multivariate resampling method to multiple regression. Multiple Linear Regression Viewpoints, 35(1), 1-5.
  6. Bai, H., Pan, W., Wang, L., & Ritchey, P. N. (2010). Another look at resampling: Replenishing small samples with virtual data through S-SMART. Journal of Modern Applied Statistical Methods, 9(1), 181-197.
  7. Bai, H., Sivo, S. A., Pan, W., & Fan, X. (2016). Application of a new resampling method to SEM: A comparison of S-SMART with the bootstrap. International Journal of Research & Method in Education, 39(2), 194-207.

Measurement and Evaluation

Together with faculty and students, we have modified a content validity index [1], studied the bidimensionallity of an anxiety scale [2], adapted and cross-validated instruments for different populations [3,4,5], and pilot tested a few instruments for further investigation [6,7].

  1. Wilson, F. R., Pan, W., & Schumsky, D., A. (2012). Recalculation of the critical values for Lawshe’s content validity ratio. Measurement and Evaluation in Counseling and Development, 45(3), 197-210.
  2. Bai, H., Wang, L., Pan, W., & Frey, M. (2009). Measuring mathematics anxiety: Psychometric analysis of a bidimensional affective scale. Journal of Instructional Psychology, 36(4).
  3. Xu, Y., Savage, C., Toobert, D., Pan, W., & Whitmer, K. (2008). Adaptation and testing of instruments to measure diabetes self-management in people with type 2 diabetes in Mainland China. Journal of Transcultural Nursing, 19(3), 234-242.
  4. Xu, H., Straughan, P., Pan, W., Zhen, Z., & Wu, B. (2017). Validating a scale of health beliefs in regular check-ups among Chinese older adults. Journal of Transcultural Nursing, 28(5), 464-472.
  5. Dardas, L., Xu, H., Shawashreh, A., Franklin, M., Wainwright, K., & Pan, W. (2019). Psychometric properties and factor structure of the Center for Epidemiologic Studies Depression Scale in a national sample of Arab adolescents. Issues in Mental Health Nursing, 40(5), 437-443.
  6. Lombardi, M., Spratling, R., Pan, W., & Shapiro, S. (2018). Measuring organizational capacity to accelerate healthcare innovation in academic health centers. Quality Management in Health Care, 27(1), 1-7.
  7. Hirschey, R., Pan, W., Kimmck, G., Hockenberry, M., Shaw, R., & Lipkus, I. (2019). What do breast cancer survivors expect from exercise? Cancer Nursing: An International Journal for Cancer Care, 42(1), e15-e19.

Key Applied Research

Substance Use and Abuse

Through meta-analysis, my applied research has had a significant contribution to prevention and treatment for substance use and abuse. For example, I conducted a meta-analysis of telephone counseling for smoking cessation [1] and the meta-analytic research has been cited numerous times. Another meta-analysis of the effectiveness of the Drug Abuse Resistance Education (D.A.R.E.) program [2] has been cited many times and was featured in media as empirical evidence for the debate on the effectiveness of the D.A.R.E. program [3,4]. Also, through collaborative research on funded projects on substance use and abuse, I have co-authored many publications on the related topics, such as smoking [5], alcohol use [6], and nicotine dependence [7].

  1. Pan, W. (2006). Proactive telephone counseling as an adjunct to minimal interventions in smoking cessation: A meta-analysis. Health Education Research, 21, 416-427.
  2. Pan, W., & Bai, H. (2009). A multivariate approach to a meta-analytic review of the effectiveness of the D.A.R.E. Program. International Journal of Environmental Research and Public Health, 6(1), 267-277.
  3. Lima News. (January 7, 2017). Do we D.A.R.E.? Local cops put their hope in oft-criticized program, by Amy Eddings.
  4. Naples Daily News. (December 25, 2011). Collier remains committed to D.A.R.E. program while others abandon it – POLL, by Jacob Carpenter. news/ 2011/dec/25/collier-remains-committed-to-dare-program-while/
  5. Stöffelmayr, B. E., Wadland, W. C., & Pan, W. (2003). An examination of the process of relapse prevention therapy designed to aid smoking cessation. Addictive Behaviors, 28, 1351-1358.
  6. Sale, E., Sambrano, S., Springer, J. F., Peña, C., Pan, W., & Kasim, R. (2005). Family protection and prevention of alcohol use among Hispanic youth at high risk. American Journal of Community Psychology, 36, 195-205.
  7. Lipkus, I. M., Schwartz-Bloom, R., Kelley, M. J., & Pan, W. (2015). A preliminary exploration of college smokers’ reactions to nicotine dependence genetic susceptibility feedback. Nicotine & Tobacco Research, 17(3), 337-343.

Application of Advanced Statistical Modeling

I have utilized advanced statistical modeling, such as multilevel modeling [1-12], structural modeling [13-21], and latent variable modeling [22-29], in collaborative applied research across different fields from health [4-12,15, 16, 18-29] to psychology [1, 13-14] to education [2,3,17] on various health and behavioral conditions from diabetes [5,15,16,20] to cancer [12,22,24-26,28,29] to aging [6-8,10,11,18] to distress [1,9,13,21,29] in hertergenous populations from children [9,23-26,28] to young adults [2-4,14,17,27] to adults [1,5,12,13,15,16,19-21,29] to older adults [6-8,10,11,18].

  1. Rye, M. S., Pargament, K. I., Pan, W., Yingling, D. W., Shogren, K. A., & Ito, M. (2005). Can group interventions facilitate forgiveness of an ex-spouse? A randomized clinical trial. Journal of Consulting and Clinical Psychology, 73, 880-892.
  2. Pan, W., Guo, S., Alikonis, C., & Bai, H. (2008). Do intervention programs assist students to succeed in college? A multilevel longitudinal study. College Student Journal, 42(1), 90-98.
  3. Bai, H., & Pan, W. (2009). A multilevel approach to assessing the interaction effects on college student retention. Journal of College Student Retention: Research, Theory & Practice, 11(2), 287-301.
  4. Guo, J. J., Wade, T. J., Pan, W., & Keller, K. N. (2010). School-based health centers: Cost-benefit analysis and impact on health care disparities. American Journal of Public Health, 100(9), 1617–1623.
  5. Luo, H., Pan, W., Sloan, F., Feinglos, M., & Wu, B. (2015). Forty-year trends of tooth loss among American adults with and without diabetes mellitus: An age-period-cohort analysis. Preventing Chronic Disease, 12(E211), 1-11.
  6. Cary, M. P., Jr., Pan, W., Bettger, J., Merwin, E., Sloane, R., & Anderson, R. (2016). Self-care and mobility following post-acute rehabilitation for older adults with hip fracture: A multilevel analysis. Archives of Physical Medicine and Rehabilitation, 97(5), 760-771.
  7. Colón-Emeric, C. S., Corazzini, K., McConnell, E., Pan, W., Toles, M., Hall, R., Batchelor-Murphy, M., Yap, T., Anderson, A. L., Burd, A., & Anderson, R. A. (2017). Study of individualization and bias in nursing home fall prevention practices. Journal of the American Geriatrics Society, 65(4), 815-821.
  8. Colón-Emeric, C. S., Corazzini, K., McConnell, E. S., Pan, W., Toles, M., Hall, R., Cary, M. C., Jr., Batchelor-Murphy, M., Yap, T., Anderson, A., Burd., A., Amaresekara. S., & Anderson, R. A. (2017). Effect of promoting high-quality staff interactions on fall prevention in nursing homes: A cluster-randomized trial. JAMA-Internal Medicine, 177(11), 1634-1641.
  9. Gondwe, W. K., White-Traut, R., Brandon, D., Pan, W., & Holditch-Davis, D. (2017). The role of sociodemographic factors in maternal psychological distress and mother-preterm infant interactions. Research in Nursing and Health, 40(6), 528-540.
  10. Li, J., Xu, H., Pan, W., & Wu, B. (2017). Association between tooth loss and cognitive decline: A 13-year longitudinal study of Chinese older adults. PLOS ONE, 12(2): e0171404.
  11. Colón-Emeric, C. S., Corazzini, K., McConnell, E. S., Pan, W., Toles, M., Hall, R., Batchelor-Murphy, M., Yap, T., Anderson, A., Burd., A., Amarasekara, S., & Anderson, R. A. (2018). Resident vignettes for assessing care quality in nursing homes. Journal of the American Medical Directors Association, 19(5),405-410.
  12. Hirschey, R., Kimmick, G., Hockenberry, M., Shaw, R., Pan, W., Page, C., & Lipkus, I. (2018). A randomized phase II trial of MOVING ON: An intervention to increase exercise outcome expectations among breast cancer survivors. Psycho-Oncology, 27(10), 2450-2457.
  13. Stoia-Caraballo, R. M., Rye, M. S., Pan, W., Kirschman, K. J. B., Lutz-Zois, C., & Lyons, A. M. (2008). Negative affect and anger rumination as mediators between forgiveness and sleep quality. Journal of Behavioral Medicine, 31(6), 478-488.
  14. Tang, M., Pan, W., & Newmeyer, M. (2008). Factors influencing high school students’ career aspirations. Professional School Counseling, 11(5), 285-295.
  15. Xu. Y., Toobert, D., Savage, C., Pan, W., & Whitmer, K. (2008). Factors influencing diabetes self-management in Chinese people with type 2 diabetes. Research in Nursing & Health, 31(6), 613-625.
  16. Xu, Y., Pan, W., & Liu, H. (2011). The role of acculturation in diabetes self-management among Chinese Americans with type 2 diabetes. Diabetes Research and Clinical Practice, 93(3), 363-370.
  17. Hwu, F., Pan, W., & Sun, S. (2014). Aptitude-treatment interaction effects on explicit rule learning: A latent growth curve analysis. Language Teaching Research, 18(3), 294-319.
  18. Lee, K.-H., Plassman, B., Pan, W., & Wu, B. (2015). Mediation effect of oral hygiene on the relationship between cognitive function and oral health in older adults. Journal of Gerontological Nursing, 42(5), 30-37.
  19. Xavier, R. M., Pan, W., Dungan, J., Keefe, R., & Vorderstrasse, A. (2018). Unraveling interrelationships among psychopathology symptoms, cognitive domains and insight dimensions in chronic schizophrenia. Schizophrenia Research, 193, 83-90.
  20. Pan, W., Ge, S., Xu, Y., & Toobert, D. (2019). Cross-validating a structural model of factors influencing diabetes self-management in Chinese Americans with type 2 diabetes. Journal of Transcultural Nursing, 30(2) 163–172.
  21. Relf, M. V., Pan, W., Edmonds, A., Ramirez, C., Amarasekara, S., & Adimora, A.A. (2019). Discrimination, medical distrust, stigma, depressive symptoms, antiretroviral medication adherence, engagement in care, and quality of life among women living with HIV in North Carolina: A mediated structural equation model. Journal of Acquired Immune Deficiency Syndromes, 81(3), 328-335.
  22. Hockenberry, M. J., Hooke, M. C., Rodgers, C., Taylor, O., Koerner, K. M., Mitby, P., Moore, I., Scheurer, M. E., & Pan, W. (2017). Symptom trajectories in children receiving treatment for leukemia: A latent class growth analysis with multitrajectory modeling. Journal of Pain and Symptom Management, 54(1), 1-8.
  23. Winkler, R. M., Park, J., Pan, W., Brandon, H. D., Scher, M., & Holditch-Davis, D. (2017). Does preterm period sleep development predict early childhood growth trajectories? Journal of Perinatology, 37(9), 1047-1052.
  24. Hockenberry, M. J., Moore, I., Scheurer, M., Hooke, M. C., Taylor, O., Koerner, K., Gundy, P., & Pan, W. (2018). Influence of nitrosative stress on fatigue during childhood leukemia treatment. Biological Research for Nursing, 20(4), 403-409.
  25. Hooke, M. C., Rodgers, C., Taylor, O., Koerner, K. M., Mitby, P., Moore, I., Scheurer, M. E., Hockenberry, M. J., & Pan, W. (2018). Physical activity, the childhood cancer symptom cluster – leukemia, and cognitive function: A longitudinal mediation analysis. Cancer Nursing: An International Journal for Cancer Care, 41(6), 434-440.
  26. Hockenberry, M. J., Pan, W., Scheurer, M. E., Hooke, M. C., Taylor, O., Koerner, K., Montgomery, D., Whitman, S., Mitby, P., & Moore, I. (2019). Influence of inflammatory and oxidative stress pathways on longitudinal symptom experiences in children with leukemia. Biological Research for Nursing. 21(5):458-465.
  27. Kayle, M., Docherty, S. L., Sloane, R., Tanabe, P., Maslow, G., Pan, W., & Shah, N. (2019). Transition to adult care in sickle cell disease: A longitudinal study of characteristics and disease severity. Pediatric Blood & Cancer, 66(1), e27463.
  28. Rodgers, C., Hooke, M. C., Taylor, O., Koerner, K. M., Mitby, P., Moore, I., Scheurer, M. E., Hockenberry, M. J., & Pan, W. (2019). Childhood cancer symptom cluster: Leukemia and health-related quality of life. Oncology Nursing Forum, 46(2), 228-237.
  29. Yang, Y., Pan, W., Allen, D. H., & Hendrix, C. C. (2019). Caregiver burden as a mediator between emotional distress and concentration problems in patients with cancer. Oncology Nursing Forum, 46(6), E180-E184

Selected Funded Grants

Currently Active

  • R01-HD098095, Co-Investigator (MPIs: White-Traut, Brandon, & Norr), Implementation of an Evidence-based Parentally Administered Intervention for Preterm Infants, 4/15/2020-3/31/2025
  • R21-TW012007, Co-Investigator (MPIs: Relf & Nyblade), Efficacy Testing of a Culturally Relevant Stigma Intervention in WLWH in Tanzania, 9/15/2021-5/30/2023
  • R01-NR018841, Co-Investigator (MPIs: Potosky & Reeve), Elucidating the Prevalence, Etiology, and Trajectories of Symptom Clusters in Early Cancer Survivors, 3/1/2020-2/28/2023
  • R21-TW011247, Co-Investigator (MPIs: Relf & Nyblade), Acceptability of an Internalized Stigma Reduction Intervention among Women Living with HIV in Tanzania, 4/15/2019-2/28/2022

Recently Completed

  • R21-DA044249, Co-Investigator (PI: Lipkus), Exploring Reactions to Health Warnings on Waterpipe Tobacco Ads, 7/1/2018-10/31/2020.
  • R01-MD010354, Subcontract Principal Investigator (PI: Merwin – University of Texas-Arlington), Reducing Health Disparities in SMI, Rural and Minority Populations, 4/1/2019-11/30/2020
  • R01-HL118189, Contact Principal Investigator (MPIs: Pan, Johnson, & Vorderstrasse), Diabetes Self-Management & Support LIVE (Learning in Virtual Environments), 06/01/2013-05/31/2019
  • R01-CA169398, Co-Investigator (MPI: Hockenberry & Scheurer), Phenotypic-Genotypic Associations with Symptom Clusters During Childhood Leukemia Treatment, 9/20/2012-7/31/2018
  • R01-NR003178, Co-Investigator (MPIs: Anderson & Colón-Emeric), Outcomes of Nursing Management Practice in Nursing Homes, 9/1/2011-10/31/2017

Please see My Bibliography for a complete list of my published work.